5,742 research outputs found
Fixed Point Theorems Using Interpolative Boyd-Wong Type Contractions And Interpolative Matkowski Type Contractions on Partial Sb-Metric Space
Get PDFIn this article, we define and explore the topological properties of partial
Sb-metric space. We define interpolative Boyd-Wong type contraction and
interpolative Matkowski type contractions in the setting of partial Sb-metric
space and obtain fixed point results for the same
Multivariate moments and Cochran theorems.
Get PDFThis thesis is divided into two related parts: (I) Moments. For a multivariate elliptically contoured random matrix Y\sim MEC\sb{n\times p}(\mu,\ \Sigma\sb{Y},\ \phi), formulae for finding the higher order moments of both Y and its quadratic forms are obtained in terms of \mu,\ \Sigma\sb{Y} and where \Sigma\sb{Y} is not required to have the form These results are so general that they are new even for the normal setting. Specific worked out examples on moments are given for both normal and certain non-normal settings such as multivariate uniform distributions, symmetric multivariate Pearson Type VII distributions, generalized Wishart distributions, multivariate components of variance models and MANOVA models. The proofs involve linear operators in inner product spaces, Kronecker products, multilinear differential forms and adjoint operators of the linear functions. (II) Cochran theorems. For a family of quadratic forms, \{Q\sb{i}(Y)\}\sbsp{i=1}{\ell}, of Y with Q\sb{i}(Y)=Y\sp\prime W\sb{i}Y+B\sbsp{i}{\prime}Y+Y\sp\prime C\sb{i}+D\sb{i},\ W\sb{i} symmetric and Y\sim N\sb{n\times p}(\mu,\ \Sigma\sb{Y}), necessary and sufficient conditions are obtained under which \{Q\sb{i}(Y)\} is an independent family of Wishart W\sb{p}(m\sb{i},\Sigma,\lambda\sb{i}) random matrices, (*). Such a result is referred to as a Cochran theorem. The Cochran theorems just mentioned are general in that the covariance matrix \Sigma\sb{Y} need not take the form and need not be positive definite. Some of these results are extended further to the case where either (i) W\sb{p}(m\sb{i},\Sigma,\lambda\sb{i}) in (*) is replaced by DW\sb{p} (m\sb{1i},m\sb{2i},\Sigma,\lambda\sb{1i},\lambda\sb{2i}), the distribution of the difference of two independent Wishart random matrices Q\sb{1i} and Q\sb{2i} with Q\sb{1i}\sim W\sb{p}(m\sb{1i},\Sigma,\lambda\sb{1i}) and Q\sb{2i}\sim W\sb{p}(m\sb{2i},\Sigma,\lambda\sb{2i}), or (ii) Y is multivariate elliptically contoured distributed. The proofs involve linear operators in inner product spaces, Moore-Penrose inverses, projections, inclusion maps, spectra, invariant measures and conditional expectations.Dept. of Mathematics and Statistics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .W358. Source: Dissertation Abstracts International, Volume: 54-09, Section: B, page: 4762. Adviser: Chi Song Wong. Thesis (Ph.D.)--University of Windsor (Canada), 1993
SB-Transposition: MAR & SV40 Excision Assay
No full textAdditional contributors: Lucas Sjeklocha; Phil Wong; Betsy Kren and Clifford Steer (faculty mentors)Sleeping Beauty transposon (SB-Tn) is an effective system that incorporates genes into vertebrate (human) chromosomes without using viruses. The Excision Assay is part of a project that determines the transposition efficiency using vector backbone elements hypothesized to increase the probability of successful gene insertion. The DNA elements used are the matrix-attachment regions (MAR) and SV40 enhancer. MAR contributes to retention of the plasmid in the host nucleus by interacting with the host nuclear proteins; SV40 enhancer promotes a high translocation rate of the SB-Tn vector into the host nucleus. The vector backbone also expresses the obligate SB transposase that must be supplied in mammalian cells to cut and paste the SB-Tn from the plasmid vector into the host chromosome. Following transfection of the vector series into a human hepatocellular carcinoma cell line (huh7), the total DNA is isolated to determine the ratio of excision product plasmids (resealed vector backbone following the cutting and pasting of the SB-Tn into the host genome to the original SB-Tn vectors transfected). This approach addresses if vector backbone modifications influence persistence of the original vector and/or excision product. If the excision plasmid, containing the SB transposase is retained in the nucleus of the host cell, the continued expression might potentially lead to harmful transposition activity remobilizing the SB-Tn integrated in the host genome.Goh, Diane. (2009). SB-Transposition: MAR & SV40 Excision Assay. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/51741
Selective-Area MOCVD Growth and Carrier-Transport-Type Control of InAs(Sb)/GaSb Core-Shell Nanowires
No full textWe
report the first selective-area growth of high quality InAs(Sb)/GaSb
core–shell nanowires on Si substrates using metal–organic
chemical vapor deposition (MOCVD) without foreign catalysts. Transmission
electron microscopy (TEM) analysis reveals that the overgrowth of
the GaSb shell is highly uniform and coherent with the InAs(Sb) core
without any misfit dislocations. To control the structural properties
and reduce the planar defect density in the self-catalyzed InAs core
nanowires, a trace amount of Sb was introduced during their growth.
As the Sb content increases from 0 to 9.4%, the crystal structure
of the nanowires changes from a mixed wurtzite (WZ)/zinc-blende (ZB)
structure to a perfect ZB phase. Electrical measurements reveal that
both the n-type InAsSb core and p-type GaSb shell can work as active
carrier transport channels, and the transport type of core–shell
nanowires can be tuned by the GaSb shell thickness and back-gate voltage.
This study furthers our understanding of the Sb-induced crystal-phase
control of nanowires. Furthermore, the high quality InAs(Sb)/GaSb
core–shell nanowire arrays obtained here pave the foundation
for the fabrication of the vertical nanowire-based devices on a large
scale and for the study of fundamental quantum physics
Origin of the low thermal conductivity of the thermoelectric material beta-Zn(4)Sb(3): An ab initio theoretical study
No full textBy modeling beta-Zn(4)Sb(3) material as a Zn(36)Sb(30) crystal with defects, the crystal structure and thermal properties of beta-Zn(4)Sb(3) are studied by ab initio method to explain its extremely low thermal conductivity at moderate temperature. The formation and migration energies of defects are calculated and used to explain the partial occupation of Zn at the lattice sites, the disordered local structures and the origin of the low thermal conductivity of beta-Zn(4)Sb(3). Our study also unravels the puzzling dependence of thermal conductivity on doping in beta-Zn(4)Sb(3). A doping strategy is proposed to improve the thermoelectric performance of beta-Zn(4)Sb(3). (C) 2011 American Institute of Physics. [doi:10.1063/1.3599483
Preparation and structural analysis of SnTe/Sb composition modulated structures
No full textA new composition modulated structure composed of semiconducting SnTe and semimetallic Sb has been grown epitaxially on mica substrates with differing SnTe to Sb ratios. The samples were characterized by x-ray diffraction using the transmission Laue patterns and θ-2θ diffractometer scans with scattering vectors both normal and in the plane of the film. We observed that the modulation satellites were 180°out of phase for films with short modulation wavelengths, but were in phase for long wavelengths. This change in the phase of the modulation can be understood by assuming that Sb adopts a quasicubic structure at short modulation wavelength, due to the coherency strain, but relaxes back to a distorted rhombohedral structure, with the loss of coherency, at long wavelengths. A simple 1-D model was used to estimate the modulation wavelength dependence of the sublattice displacement of Sb.</p
Stability of Sb-Te layered structures: First-principles study
Get PDFUsing an effective one-dimensional cluster expansion in combination with first-principles electronic structure calculations we have studied the energetics and electronic properties of Sb-Te layered systems. For a Te concentration between 0 and 60 at. % an almost continuous series of metastable structures is obtained consisting of consecutive Sb bilayers next to consecutive Sb2Te3 units, with the general formula (Sb2)n(Sb2Te3)m (n,m=1,2,...). Between 60 and 100 at. % no stable structures are found. We account explicitly for the weak van der Waals bonding between Sb bilayers and Sb2Te3 units by using a recently developed functional, which strongly improves the interlayer bonding distances. At T=0 K, no evidence is found for the existence of two separate single-phase regions ? and ? and a two-phase region ?+?. Metastable compounds with a Te concentration between 0 and 40 at. % are semimetallic, whereas compounds with a Te concentration between 50 and 60 at. % are semiconducting. Compounds with an odd number of Sb layers are metallic and have a much higher formation energy than those with an even number of consecutive Sb layers, thereby favoring the formation of Sb bilayers.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Legal and Financial Problems of International Joint Custody of Children
Get PDFThe aim of this article is to analyze very interesting and currently up-to-date area of children living in international joint custody from the legal and financial point of view. This covers the situation when custody of a child is awarded to both parents living in different states of the European Union (or also other states). The number of marriages contracted between Czech nationals and foreign nationals and also between nationals from two different states (not necessarily inside European Union) increases every year while free movement of people is a real practice today. Because these international marriages are becoming more common they bring new problems that must be solved by contemporary law. This regulation needs to result from the knowledge of the children psychology that is affecting family law the most but also has its practical aspects in the area of taxation and payment issues that will be analyzed deeply as well.juridical problems, financial problems, international joint custody, family.
Nonlinear influence of excess Mn on the magnetoelastic transition in (Mn,Cr)<sub>2</sub>Sb
No full textThe influence of excess Mn on the magnetoelastic ferromagnetic-to-antiferromagnetic transition Tt in the magnetocaloric compound (Mn,Cr)2Sb has been studied. With increasing excess Mn the magnetoelastic transition temperature for (Mn,Cr)2Sb initially increases and then decreases. This trend is accompanied by a strong reduction of the (Mn,Cr)Sb secondary phase. With increasing excess Mn a higher Cr content was found in the (Mn,Cr)Sb secondary phase in comparison to the matrix phase. This competition for Cr leads to a nonlinear dependence of Tt with increasing excess Mn at a fixed nominal Cr content. However, we observed that Tt depends linear on the c/a ratio for a wide range of temperatures from 170 to 350 K. A compositional diagram of the c/a ratio was constructed to assist the selection of (Mn,Cr)2Sb alloys with a desired transition temperature.RST/Fundamental Aspects of Materials and Energ
Fabrication and properties of Sb-doped ZnO thin films grown by radio frequency (RF) magnetron sputtering
No full textSb-doped and undoped ZnO thin films were deposited on Si (100) substrates by radio frequency (RF) magnetron sputtering. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed that all the films had polycrystalline wurtzite structure and c-axis preferred orientation. Room temperature Hall measurements showed that the as-grown films were n-type and conducting (rho similar to 1-10 Omega cm). Annealing in a nitrogen ambient at 400 degrees C for 1 h made both samples highly resistive (rho > 10(3) Omega cm). Increasing the annealing temperature up to 800 C, the resistivity of the ttndoped ZnO film decreased gradually, but it increased for the Sb-doped ZnO film. In the end, the Sb-doped ZnO film annealed at 800 C became semi-insulating with a resistivity of 10(4)Omega cm. In addition, the effects of annealing treatment and Sb-doping on the structural and electrical properties are discussed. (c) 2006 Elsevier B.V. All rights reserved
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